Rebuilding rear calipers

[DDS]

Anybody know what kind of grease is used in the parking brake mechanism? The stuff in mine is kind of a silvery blue colour, and is fairly resistant to varsol and the like. Does it matter?
Any suggestions on re-greasing or on anything else in this rebuild? They are a bit trickier than fronts, but don't seem like they'll be impossible. Odd that the haynes manual says that they can't be rebuilt.
Anyone know the torque on the screws holding the halves together?
Many TIA.

Dave

[HMeeder]

Dave:

A few months back I wrote a tech article on the rear caliper re-build. The article is here on the tech articles part of this site. It includes the torque specs. Don't remember them off the top of my head. The only grease that I know of using is a touch of grease (even high-temp disc brake grease will be fine) on the parking brake actuator arm where it goes into the caliper. That silvery/blue stuff may be years and years (and years) of gunk/dirt/caliper particles that have built up in the brakes. All that stuff tends to settle in the parts of the calipers that don't see much fluid flow. Even a good brake system flush won't get to those nooks and crannys and they frequently won't get properly cleaned until the calipers are cracked open. Just think, you're looking at dust and dirt that traveled all the way from Germany to drive around with you. Kinda makes you nostalgic, eh?

Good Luck and don't believe everything Hayne's tells you!

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Herb
'72 1.7 Tangerine 'Teen
'74 2.0 Red Rustmobile

[DDS]

Thanks Herb, must have missed the article. Funny that Haynes stays away from that one, the rears are more complicated than yer basic caliper, but aren't that bad.
The grease in question is actually inside the caliper. It is used to lubricate the adjuster mechanism and the little pill-like link that engages the inboard piston. It exists in the space between the inboard piston and the p-brake lever shaft. It was quite clean and looks the same as the grease on my shifter mech. Genuine old German grease... Sigh.

Dave

[DDS]

Excellent article Herb, thanks. One thing to add. My fancy circlip pliers couldn't reach into the bore, so I used the mighty Dremel to grind a pair of long, fine needle-nose pliers into the perfect tool. Just keep rotating the pliers lathe-like against a grinding wheel, then relieve the inside edges. Doing the chop-stick thing would have made me crazy.
Also, I was told that if you turn the adjusters to retract the pistons, and keep turning just a few more times, you can destroy the mechanism within. Haven't tried THAT yet.

Did you paint your calipers?

Dave

[HMeeder]

Dave:
Thanks for the tip. I have a couple of old needle nose around that I can sacrifice. I hadn't heard about ruining the adjusters when cranking them around. I did have just a touch of trouble when compressing the pistons back in but they "caught" on the 2nd try.

I did not paint my calipers, but when I get around to rebuilding the ones one my '72 (another project, another day) I plan to paint them (I thought that red would look good with my wheels.) I read that Wurth has paint that they formulated for brake calipers (comes in silver, black, red and I believe orange.) Anyone have any experience with caliper painting that they would like to share????


------------------
Herb
'72 1.7 Tangerine 'Teen
'74 2.0 Red Rustmobile

[Scott S]

Hi Herb -
I painted my calipers (red) a few years back. I used the Eastwood caliper paint. I really liked it until all of the slammed Hondas got into the act. I recently finished a 5 bolt conversion. I cleaned up the calipers and repainted them using the Eastwood gold cad system. The look like they are new from the factory, and look great (and appropriate)behind those 8" 911 fuchs wheels. I highly reccommend it.
Scott S

[DDS]

I bought some Plasikote Caliper paint from UAP/Napa - Rapmobile Red and am in the process of painting my front "A" calipers and will tackle the rears next. BTW I tracked down the mysterious RIBE tools at UAP from a company called Unitool - part no UT35 for 6mm, and UT36 for 8mm. Cheap like Borscht. Total cost for one of each $14CDN or about 8 bucks. These are bits that can be inserted in a 5/16" socket.
Dave

[DDS]

It would appear that SC calipers use the 6mm Ribe and 914 calipers use a smaller one. 4mm?

[TDC914]

Is there any way to recover from backing the adjuster back too much, as DDS describes below?
I just replaced my rear brake pads, and now I cannot adjust one of the pads, (inside right side). The other pads adjusted fine, but the right inside pad will not move in when tuning the adjusting screw. Even with new Pads the venting clearance is still too large and the Parking brake will not grab on that side. However, the brakes seem to be grabbing fine when using the brake pedal.

Does rebuilding the caliper help to reset the adjuster, or is completely hosed?

Also, 911 Rear Pads are the same size as 914 rear pads except, the 914 has one of the pin holes slight larger. Is there any problem with drilling holes larger on the 911 pads to make it fit the 914?

Originally posted by DDS:
...
Also, I was told that if you turn the adjusters to retract the pistons, and keep turning just a few more times, you can destroy the mechanism within. Haven't tried THAT yet.
...
Dave[/b]

[This message has been edited by TDC914 (edited 07-08-2001).]